Forming truing apparatus



Jan. 14, 1941. J. OLSON 2,229,016

FORMING TRUING APPARATUS Filed April 27, 1940 2 Sheeiis-Sheet 1 IHHHIHIIIHIHHHI JOHN 71. SUN

Jan. 14, 1941. YJ. OLSON 2,229,016

FORMING TRUING APPARATUS Filed April 27, 1940 2 Sheets-Sheet 2 FIT" I :j II I Patented Jan. 14, 1941 UNITED STATES FORMING TRUING APPARATUS John Olson, Leicester, Mass,

Company, Worcester, Mass,

Massachusetts assignor to Norton a corporation of Application April 27, 1940, Serial No. 331,954

3 Claims.

The invention relates to forming truing apparatus particularly for forming steep depressions in a grinding wheel.

One object of the invention is to provide a forming truing apparatus of the nature indicated which shall form a more perfect surface on the grinding wheel. Another object of the invention is to eliminate gouges in the surface of the wheel. Another object of the invention is to provide an improved latch for a forming truing apparatus. Another object is to improve the forming bar of patent to D. W. Martin No. 2,187,690. Another object of the invention is to improve the forming truing apparatus of Silven and Cole application Serial No. 256,320. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features, of construction, combinations of elements. and arrangements of parts as will be exemplified in the structure to be hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings illustrating one of many possible embodiments of the mechanical features of this invention,

Figure 1 is a front elevation of a grinding machine incorporating the forming truing appa-.

ratus of the invention;

Figure 2 is a view partly in side elevation and partly in vertical axial section of the forming truing apparatus, the section being taken along the line 2-2 of Figure 4.

Figure 3 is a perspective view of the latches certain parts being arbitrarily spaced apart in order more clearly to show the construction.

Figure 4 is a front elevation of the forming truing apparatus.

Figure 5 is an enlarged elevation of the forming bar.

Figure 6 is a plan view of the forming bar.

Figure 7 is a vertical sectional view through the forming bar taken on the line 'I-'l of Figure 6.

As conducive to a clearer understanding of the present invention it is noted that the forming truing apparatus of the aforementioned Martin patent is highly effective to shape a grinding wheel. In the patent the apparatus is shown applied to the footstock of a grinding machine. I have herein shown my forming truing apparatus applied to the wheel slide more in accordance with the disclosure in the Silven and Cole application referred to, but the particular forming truing apparatus above to be described might, as in the Martin patent, be applied to the footstock and might be applied elsewhere in the grinding ma chine.

While as above stated the forming truing apparatus of the Martin patent in general operates satisfactorily, there was one latent difficulty there- 5 with which was not perceived at once. This lay in the fact that in order to make the latch operate properly, retrograde movement of the truing tool and the follower caused a slight jogging of the forming tool slide as the follower went over 10 the operating shoulder of the latch thus creating an undesired depression in the wheel. In accordance with the present invention I have overcome this defect without losing any of the advantages of the apparatus of the Martin patent.

Considering now the general structure of a grinding machine. truing apparatus and slides to which my invention may be applied, Figure 1 illustrates in somewhat conventional form a cylindrical grinding machine. The forming truing apparatus of the invention may be applied to many different types of grinding machines but has particular utility in connection with cylindrical grinding machines. It may be applied to automatic grinders, but I disclose herein a hand operated grinding machine since the automatic features may be applied without interference with the forming truing apparatus of the invention. As illustrated in Figure 1, the grinding machine may comprise a base Ill supporting for reciprocation or longitudinal adjustment a carriage H which supports a table 12 which may be fastened to the carriage I l in various positions of angular adjustment, as is well known in the art. Adjustably fastened to the table l2 along ways I3 is a headstock I4 and also a tailstock I5. The headstock l4 may support a driving motor It adapted to rotate a face plate ll through gearing contained in a gear casing l8 and a spindle l9 which is journalled in the headstock l4. Projecting from the face plate I! is a work holding center 2!] in line with and opposite a tail center 2! mounted in the tailstock [5. By means of a hand wheel 22 the tail center 2! may be advanced and retracted toward and from the head center 2! through the medium of screw means, not shown but well known. When the work piece W has been centered in the machine, a lever 23 is used to clamp the tailstock 2| firmly in adjusted position.

For longitudinal adjustment of the carriage ll there may be provided any suitable device, such as a hand wheel 25 having a pinion gear operating a spur gear 21 which is connected to a pinion gear 28 meshing with a rack 29 fastened to the under side of the carriage II. The forming truing aptween the grinding wheel and the work piece. Such a grinding operation will form the work piece to a complement or conjugate of the shaped grinding wheel. The hand wheel 25 is used to position the work piece W in the exact desired longitudinal position with respect to the grinding element in order to produce the shaped portion on the work piece in the desired position axially.

Still referring to Figure 1, I show a grinding wheel 30 mounted on a spindle, not shown, journalled in awheel head 32, the grinding wheel being rotated by a motor 33 and suitable belting in a casing 34 connected to a pulley on the righthand end of the wheel spindle. I have not shown the wheel spindle and wheel head in any more detail because any conventional drive and support for the grinding wheel may be used, such being well known in the art. In order that the wheel '30 may be fed transversely relative to the work piece W, there is provided a cross feed shaft 35 on which is mounted a ratchet 36 operated by a pawl 31 which is actuated by a cylinder piston hydraulic unit 38. Any other cross feeding mechanism may be substituted for that indicated.

I provide a massive wheel guard 45. This wheel guard 45 is attached to the wheel head 32 and has a large opening 5| at the top bridged by a plate '2 having a smaller opening 43. Fastened to the wheel guard 40 on the upper side thereof, as is best shown at the left-hand side of Figure 2, is a truing base 45. As shown, this base has an upwardly rising inclined web portion 45, a curved portion il, a pair of bosses 48, and an upper plate portion 49. Still referring to Figure 2, longitudinally centrally disposed in the bottom part of the curved portion 41 is a pivot pin 55. Pivotally mounted on the base portion 45 by means of this pivot pin is a slideway 5| receiving a cylinder 52. The angular adjustment in a vertical plane of the slideway 5! may be effected by screws 53 whose lower ends engage shelves 5 3 integrally connected to the slideway 5!. This adjustment is usually for minutes of are only and in order to align the axis of the cylinder 52 with the axis of the wheel 35 more accurately than can be done by machining operations on the various castings. However, the same result can be achieved by adjusting the table i2 on the carriage II to a like degree so far as results on the Work piece are concerned.

The slideway 5! includes dovetailed portions 56 supporting a slide 51 which holds the dressing tool. The slide 51 is of generally hollow construction, as shown in Figure 2, and includes a hollow cylindrical portion 58 as well as dovetailed portions 59 fitting the dovetailed portions 56.

As indicated in dotted lines in Figure 4, a piston 50 is located in the cylinder 52 and has attached thereto a piston rod 5| fastened to a plate 62 which extends rearwardly from the slide 51.

Referring now to Figure 2, the cylindrical portion 53 removably supports a sleeve 65 having at the upper end and on the front thereof a shelf 66 and having opposite the shelf 65 at therear thereof a boss 67 to which is fastened a follower member 68 by means of a bolt 69. The sleeve 65 is slidable vertically in the cylindrical portion 58 but lost motion is preferably eliminated by means of a split bottom portion 10 of the cylindrical portion 58 controlled by a pull screw H and a push screw 72. See Figure 4 wherein the cover plate 74 of Figure 2 is removed. The shelf 56 fits between forked portions 15 of a member 16 attached to the upper part of the cylindrical portion 58 which prevents the sleeve 65 from turning in the cylindrical portion 58. The sleeve 65 is urged downwardly to keep the follower 6B in contact with the form bar hereinafter described by means of a spring fastened to a screw iii in the shelf 66 and a screw 82 in a lug 33 projecting from the cylindrical portion 58. Merely by uncoupling the spring 85 and loosening the screw H, the entire unit supported from the sleeve 65 and including the follower 68 may be removed from the machine. Supported in the upper end of the sleeve 55 is a bearing 90. This bearing is removable but may be firmly locked to the sleeve 65 as it fits within a cylindrical bore thereof including split portions 9| which can be drawn together to clamp the bearing 90. A sleeve 92 is journalled in the bearing and has keyed thereto the hub 53 of a spur gear wheel 94. The hub 93 is mounted on an upper screw threaded portion of the sleeve 92 and is locked on the sleeve 92 rigidly in a vertical direction by means of a pair of nuts 95 and 9B. The sleeve 92 is internally threaded and fits on the upper threaded portion 9'! of a quill 58 which is keyed by means of a key 99 to the sleeve 55.

Rotation of the gear 54 rotates the sleeve 92 which moves the quill 9'! vertically in the sleeve 55, as relative rotation is prevented by the key 99. Positive downward movement can be effected because the sleeve 92 has a shoulder under the bearing 95, as shown. Angular movement of the spur gear 54 is for the purpose of adjusting the vertical position of the quill 98 in the sleeve 55; the sleeve 55 moves vertically in response to actuation of the follower 58 to generate the desired contour on the work piece. A dressing diamond N15 is embedded in a nib l 0| fitting in a hole in the bottom of the quill 93 and retained therein by means of a screw I52.

For a delicate angular adjustment of the dia mond by rotation of the spur gear it, we provide a knob I53 on the bottom of a shaft I05 located in a vertical bearing I55 which is integral with a plate H16 fastened to the shelf 55. On the upper end of the shaft I54 is a pinion gear i5? meshing with the spur gear 54. A spring-pressed detent, not shown, located in a boss Hi8, enables the operator to feel the adjustment toa given tooth of the pinion gear I01 or spur gear 94.

In order to effect a dressing of the grinding wheel 30 the dressing diamond Hill is moved in the general direction of the axis of the grinding wheel-by moving the slide 51 in response to movement of the piston 65 in the cylinder 52. This may be achieved by the cylinder-piston unit actuated by any fluid pressure apparatus, for example such as diagrammatically illustrated in the application above referred to of Silven and Cole. Although the slide 5'! moves rectilineally, the diamond may be given an irregular motion in a vertical plane by a form bar I59, about to be described, acting upon the follower 68.

Referring now to Figures 5 and 6, I have a form bar I09 which has a straight front forming surface H0 merging into agradual convex curve III which in turn merges into a reentrant curve H2 followed by a convex portion I I3 having a very steep incline H4 adjacent a perfectly straight portion H5. The portion H0 is nearly but not quite parallel to the motion given by the cylinder piston unit, while the portion H5 is parallel thereto. The follower member 58 will ride over all the portions excepting the portion shown lit with no difficulty because they are none of them inclined at more than forty-five degrees to the line of movement of the carriage ll. When it comes to the portion li t the follower member til will readily move over it to the left (Figures and 6) but since the portion i it makes an angle with the straight portion it of more than fortyfive degrees, the follower member G3 will not ride by this surface ll l to the right without deforming the parts or possibly breaking one or more of them. I provide a latch lZll to by-pass the follower 58 away over the surface ll l.

Referring now particularly to Figure 3, the latch it?! is suitably fastened to a rock shaft i2! which, as better shown in Figures 5 and 6, is journalled in the form bar are. As shown in Figure 7 this latch I2 is located in a recess I22 in the form bar tilt and when in its operating position secants the portion H4. Consequently the latch if?!) is supposed to be thrown entirely within the recess M2 when the follower 68 moves to the left but to be automatically returned to the secanting position prior to movement of the follower (iii to the right. This is accomplished by an irregular shaped detent lit which is loose on the shaft it'll and has a detent point lflt which will be engaged by the follower it in either direction of movement thereof. The follower (i8 is wide enough to extend across the recess I22 and behind the form car over the detent I23.

I further provide an operating arm i215 which is suitably clamped to the rock shaft iii and has a surface lit; for engagement by a pin l2"! extending laterally from a portion of the detent li t. The operating arm I25 has attached to it a spring lit which is anchored to a pin i 29 extending rearwardly from the form bar are. Thus the operating arm 125 is urged in a clockwise direction normally placing the latch l2il against a stop pin use which extends across the recess i122. When the follower B8 strikes the detent point I2 1 of the detent I23, the detent 723 is rotated counterclockwise and in turn rotates the operating arm 125 by reason of the fact that the pin I21 extending laterally from the detent I23 is in contact with the surface I26 of the operating arm I25. So, therefore, the follower rotates the detent which rotates the operating arm which rotates the latch I thus moving it out of the way of the follower and it will be noted that the detent point I24 is spaced slightly ahead of the leading edge of the latch no. The detent 123 is maintained relatively to the operating arm I25 in the position shown in the drawings, particularly Figure 3, by means of a spring ltl extending from the right-hand end portion of the operating arm I25 to a pin I32 extending laterally from the detent I23.

In the retrograde motion of the follower til it finds the latch secanting the form bar surface IM and rides over it as the latch lfll forms an easier incline than provided by the portion HA. The grinding wheel of course was shaped in the movement of the parts to the left. But the latch I25) may be correlated to the surface of the form bar I09 to give a very smooth ride to the diamond because the projection that the follower 68 strikes is not on the latch i253 but is on a separate part, namely the detent i213. Eventually in the righthand movement of the follower til it strilres the detent point li t but this is wholly harmless since the detent lift merely rocks slightly clockwise, the pin l2l lifting from the surface lit and the spring ltl expanding slightly. When the follower has finally released the detent it simply springs back to its original position, as shown in Figure 3 for example.

Referring now to Figures 5 and e I have shown duplicate parts at the right-hand side of the form bar lilt which may briefly be identified as latch lfiila, shaft lllla, recess Hills, detent illila, detent point ii la, operating arm lied, spring lflta, pin lite, stop pin lilila. These parts are shaped similar to the correspondingly numbered parts without the identifying letter a and functicn as already described.

Itwill thus be seen that there has been provided by this invention an apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth, or shown in the accompanying drawings, is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In forming truing apparatus, a form bar, a slide, a follower carried by the slide, resilient means causing the follower to engage the form bar, a latch to lift the follower away from the form bar in one relative direction of traverse, and a separate detent arranged to be engaged by the follower and connected to move the latch out of the Way when the follower moves in the reverse direction of traverse.

2. In forming truing apparatus, a form bar, a followed to ride on said form bar, a latch to lift the follower away from the form bar, a shaft upon which said latch is mounted, a detent and an operating arm, the detent being arranged to be contacted by the follower, the detent being connected through the operating arm to the latch and spring means holding the detent resiliently in a definite relative position to the operating arm while allowing it to be moved out of such position in one direction of travel of the follower, whereby in a given direction of movement of the follower it engages the detent, rocks the operating arm which is connected to the latch and thereby removes the latch from the path of the follower, and in the opposite direction of travel of the follower the detent rocks with relation to the operating arm against the spring means.

3. In forming truing apparatus, a form bar, a slide, a follower carried by the slide, resilient means causing the follower to engage the form, a latch to lift the follower away from the form bar in one relative direction of traverse and separate means engageable by the follower to swing the latch out of the way in reverse direction of traverse.

JOHN OLSON. 

